Backpack



FIG. 1 is a first perspective view of a backpack showing my new design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof;

FIG. 8 is a bottom view thereof; and,

FIG. 9 is an enlarged view of the selected portion in FIG. 1.

The evenly dashed broken lines shown in the drawings depict portions of the backpack in which the design is embodied that form no part of the claimed design. The dash dot dash lines in FIGS. 1 and 9 depict the cut line of the sectional view and form no part of the claim. 

CLAIM The ornamental design for a backpack, as shown and described. 